Central heating problem

[SkipToMyLou]

Wondering if anyone has any ideas about this. The central heating is set to come on twice a day, and it's connected to a thermostat. In the morning, no problem. This past few days though in the evening, the green light on the thermostat comes on at the right time, but the central heating doesn't 'kick in' - I have to turn the thermostat down (so the light goes red) and then back up to the temp I want to get the boiler to start.

I replaced the timer for the heating about 4 years ago so I don't think that's the problem - could it be the thermostat?

Any ideas much appreciated, thanks!

We had to get our switch replaced - you could hear it click when the start time arrived but the boiler didn't fire up.

we are having the same issue

I'm 95% sure it's the thermostat but DH won't replace ours until it fails totally

Thanks for your input, I'm leaning towards the thermostat as yesterday the heating came on in the evening OK. I hate intermittent problems, I haven't got time to take it all apart and test everything. Much as I'd like to... grrrrr!